package com.baseweb.webadmin.core.util;

import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

public class JsonUtils {  
    public static String stringToJson(String s) {  
        if (s == null) {  
            return nullToJson();  
        }  
        StringBuilder sb = new StringBuilder();  
        for (int i = 0; i < s.length(); i++) {  
            char ch = s.charAt(i);  
            switch (ch) {  
            case '"':  
                sb.append("\\\"");  
                break;  
            case '\\':  
                sb.append("\\\\");  
                break;  
            case '\b':  
                sb.append("\\b");  
                break;  
            case '\f':  
                sb.append("\\f");  
                break;  
            case '\n':  
                sb.append("\\n");  
                break;  
            case '\r':  
                sb.append("\\r");  
                break;  
            case '\t':  
                sb.append("\\t");  
                break;  
            case '/':  
                sb.append("\\/");  
                break;  
            default:  
                if (ch >= '\u0000' && ch <= '\u001F') {  
                    String ss = Integer.toHexString(ch);  
                    sb.append("\\u");  
                    for (int k = 0; k < 4 - ss.length(); k++) {  
                        sb.append('0');  
                    }  
                    sb.append(ss.toUpperCase());  
                } else {  
                    sb.append(ch);  
                }  
            }  
        }  
        return sb.toString();  
    }  
  
    public static String nullToJson() {  
        return "";  
    }  
  
    public static String objectToJson(Object obj) {  
        StringBuilder json = new StringBuilder();  
        if (obj == null) {  
            json.append("\"\"");  
        } else if (obj instanceof Number) {  
            json.append(numberToJson((Number) obj));  
        } else if (obj instanceof Boolean) {  
            json.append(booleanToJson((Boolean) obj));  
        } else if (obj instanceof String) {  
            json.append("\"").append(stringToJson(obj.toString())).append("\"");  
        } else if (obj instanceof Object[]) {  
            json.append(arrayToJson((Object[]) obj));  
        } else if (obj instanceof List) {  
            json.append(listToJson((List<?>) obj));  
        } else if (obj instanceof Map) {  
            json.append(mapToJson((Map<?, ?>) obj));  
        } else if (obj instanceof Set) {  
            json.append(setToJson((Set<?>) obj));  
        } else {  
            json.append(beanToJson(obj));  
        }  
        return json.toString();  
    }  
  
    public static String numberToJson(Number number) {  
        return number.toString();  
    }  
  
    public static String booleanToJson(Boolean bool) {  
        return bool.toString();  
    }  
  
    /** 
     * @param bean 
     *            bean对象 
     * @return String 
     */  
    public static String beanToJson(Object bean) {  
        StringBuilder json = new StringBuilder();  
        json.append("{");  
        PropertyDescriptor[] props = null;  
        try {  
            props = Introspector.getBeanInfo(bean.getClass(), Object.class)  
                    .getPropertyDescriptors();  
        } catch (IntrospectionException e) {  
        }  
        if (props != null) {  
            for (int i = 0; i < props.length; i++) {  
                try {  
                    String name = objectToJson(props[i].getName());  
                    String value = objectToJson(props[i].getReadMethod()  
                            .invoke(bean));  
                    json.append(name);  
                    json.append(":");  
                    json.append(value);  
                    json.append(",");  
                } catch (Exception e) {  
                }  
            }  
            json.setCharAt(json.length() - 1, '}');  
        } else {  
            json.append("}");  
        }  
        return json.toString();  
    }  
  
    /** 
     * @param list 
     *            list对象 
     * @return String 
     */  
    public static String listToJson(List<?> list) {  
        StringBuilder json = new StringBuilder();  
        json.append("[");  
        if (list != null && list.size() > 0) {  
            for (Object obj : list) {  
                json.append(objectToJson(obj));  
                json.append(",");  
            }  
            json.setCharAt(json.length() - 1, ']');  
        } else {  
            json.append("]");  
        }  
        return json.toString();  
    }  
  
    /** 
     * @param array 
     *            对象数组 
     * @return String 
     */  
    public static String arrayToJson(Object[] array) {  
        StringBuilder json = new StringBuilder();  
        json.append("[");  
        if (array != null && array.length > 0) {  
            for (Object obj : array) {  
                json.append(objectToJson(obj));  
                json.append(",");  
            }  
            json.setCharAt(json.length() - 1, ']');  
        } else {  
            json.append("]");  
        }  
        return json.toString();  
    }  
  
    /** 
     * @param map 
     *            map对象 
     * @return String 
     */  
    public static String mapToJson(Map<?, ?> map) {  
        StringBuilder json = new StringBuilder();  
        json.append("{");  
        if (map != null && map.size() > 0) {  
            for (Object key : map.keySet()) {  
                json.append(objectToJson(key));  
                json.append(":");  
                json.append(objectToJson(map.get(key)));  
                json.append(",");  
            }  
            json.setCharAt(json.length() - 1, '}');  
        } else {  
            json.append("}");  
        }  
        return json.toString();  
    }  
  
    /** 
     * @param set 
     *            集合对象 
     * @return String 
     */  
    public static String setToJson(Set<?> set) {  
        StringBuilder json = new StringBuilder();  
        json.append("[");  
        if (set != null && set.size() > 0) {  
            for (Object obj : set) {  
                json.append(objectToJson(obj));  
                json.append(",");  
            }  
            json.setCharAt(json.length() - 1, ']');  
        } else {  
            json.append("]");  
        }  
        return json.toString();  
    }  
  
    public static void main(String[] args){
    	Map<String, Object> map = new HashMap<String, Object>();
    	Map<String, String> map2 = new HashMap<String, String>();
    	map2.put("第一名", "你好美丽");
    	map.put("1", map2);
    	map.put("2", "王2大嫂");
    	map.put("3", map2);
    	map.put("4", "王4大嫂");
    	
    	System.out.println(JsonUtils.mapToJson(map));
    }
}  